A receptacle is used for plugging a mating electronic device to implement an electrical connection therebetween. With more and more electric vehicles put into operation, it is necessary to consider how to improve the safety performance of charging the electric vehicles. An electric vehicle usually can be charged by plugging an external charging gun into a charging receptacle. In practice, a receptacle usually need to use a connector such as a connecting terminal or the like to establish an electrical connection. With a current passing through, the connecting terminal will generate heat. Accordingly, one question to be considered is how to monitor the heat generation of the connecting terminal.